Multiple Simultaneous Optical Frequency Measurement
Abstract
A signal processing apparatus for providing concurrent electrical frequency measurements of multiple, time-coincident signal inputs. In one embodiment of the present invention, an input signal is received that contains a plurality of individual signals independent of each other in frequency, phase, and electrical amplitude. A power splitter splits the input signal into two separate input signals. A delay line introduces a time delay to one of the two separate input signals. Two Bragg cells within a channelized optical phase measurement (COPM) device modulates two optical carrier signals with the delayed and non-delayed input signals, respectively, separating the modulated delayed and non-delayed input signals into multiple time- concurrent frequency channel signals. Upon exiting the Bragg cells, the two optical beams interfere spatially to develop an interference pattern along the phase and frequency channel number axes of a photodetector array. The resulting spatial intensity pattern phase variation is decoded to provide coarse frequency, phase, and amplitude measurements. A frequency encoder receives the photodetector outputs, corrects phase and amplitude data offsets, and converts phase to fine frequency. Finally, the frequency formatter concatenates coarse to fine frequency for readout.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 09, 2001
- Accession Number
- ADD019751
Entities
People
- Hall L. Levitt
Organizations
- United States Department of the Navy